A binder-free aluminum (Al) electrode was fabricated by electrodeposition on a three-dimensional copper foam (3DCu) or carbon fabric (3DCF) from a mixed-halide ionic liquid. The strong adhesion, structural stability and interface compatibility between Al and 3DCu facilitate high electrical conductivity and effectively alleviate large volume change. In a lithium-ion battery, the continuous, dendrite-free Al/3DCu electrode enables stable and reversible reactions, which delivered a first discharge capacity of 981 mAh g−1 in a coin cell at 21 mA g−1. It operates stably for at least 12 cycles with a discharge depth of about 1 mAh per cycle (7 h each) at the rate of 21 mA g−1. The cycled Al/3DCu electrode maintains good interfacial stability and shows no shedding. In contrast to many nanostructured electrodes, the amount of Al can reach 30% of a solid Al electrode with an average conversion to Li0.71Al. The concept of porous 3D electrodes provides a good compromise between diffusion kinetics and the total amount of active metal available in a battery with alloying-type anodes and appears promising for application.